An Etymological Dictionary of the German Language/fressen
fressen, vb., ‘to eat greedily, devour, corrode,’ from MidHG. vrëȥȥen, OHG. frëȥȥen, ‘to eat up, consume, feed,’ of men and animals; derived from an earlier *fraëȥȥan, by syncope of the unaccented a, comp. Goth. fraïtan, ‘to consume’ (E. to fret, ‘to cut away’), with the similarly shortened pret. sing. frêt, plur. frêtun, for *fraét, *fraêtun. The Goth. verbal prefix occurs in other cases in OHG. as fir, far, MidHG. and ModHG. ver, and from ëȥȥen combined with this ver a new verb, verëȥȥen, is formed in MidHG. with the same meaning as frëȥȥen, which is etymologically equiv. to it. For the verbal prefix see Frevel, ver-.